We are having many problems when working with the add-in in documents that already had other custom XMLs. When we have to select which is the XML origin of the bindings, we always end up receiving this same error and the document ends up damaged and unrecoverable for its modification with the add-in.
Please fix XML error before switching views: Root element is missing. line -1. col-1
It has nothing to do with the specific XML in this example since the same XML has worked for us in other documents.